With the evolution and successful development of the wireless local area network, people have demands to integrate the wireless local area network and the mobile cellular network together. The main purpose of this integration is to develop a new mobile data network, making the ubiquitous data services be capable of high data transmission in the wireless local area network, meanwhile the wireless local area network can reduce the pressure brought by a large number of data services to the data traffic in the mobile cellular network.
For safety reasons, however, most of the wireless local area networks use key cryptography to limit the accessing terminal. If the terminal wants to access the abovementioned wireless local area network, it needs to consult with the wireless local area network administrator about the key, for example, a customer in a restaurant or cafe consults with the salesperson about the key, and such a key acquisition mode is not only inefficient, but also vulnerable to human factors.